职教组卷基于海量职教高考试题库建立的在线组卷及学习系统
职教组卷
科目:

选择章节

总题量:2922 选择本页全部试题
  • 题型:选择题 题类:模拟题 难易度:较易

    年份:2021

    如图所示的数阵中,每行、每列的三个数均成等差数列,如果数阵中所有数之和等于\(63\),那么\(a_{52}=(\quad)\)
    \(\begin{pmatrix}a_{41}&a_{42}&a_{43}\\ a_{51}&a_{52}&a_{53}\\ a_{61}&a_{62}&a_{63}\end{pmatrix}.\)
    A.\(2\) B.\(8\) C.\(7\) D.\(4\)
  • 题型:填空题 题类:模拟题 难易度:较易

    年份:2021

    已知等差数列\(\{a_{n}\}\)的通项公式为\(a_{n}=31-tn(t\in Z)\),当且仅当\(n=10\)时,数列\(\{a_{n}\}\)的前\(n\)项和\(S_{n}\)最大.则当\(S_{k}=-10\)时,\(k=\)______.
  • 题型:解答题 题类:模拟题 难易度:较易

    年份:2021

    已知数列\(\{a_{n}\}\)满足\(a_{1}=1\),\(a_{2}=3\),\(a_{n+2}=3a_{n+1}-2a_{n}(n\in N^{*})\),
    \((Ⅰ)\)证明:数列\(\{a_{n+1}-a_{n}\}\)是等比数列;
    \((Ⅱ)\)求数列\(\{a_{n}\}\)的通项公式.
  • 题型:解答题 题类:模拟题 难易度:较易

    年份:2021

    设等差数列\(\{a_{n}\}\)的公差为\(d\),\(d\)为整数,前\(n\)项和为\(S_{n}\),等比数列\(\{b_{n}\}\)的公比为\(q\),已知\(a_{1}=b_{1}\),\(b_{2}=2\),\(d=q\),\(S_{10}=100\),\(n\in N^{*}.\)
    \((Ⅰ)\)求数列\(\{a_{n}\}\)与\(\{b_{n}\}\)的通项公式;
    \((Ⅱ)\)求数列\(\{a_{n}+b_{n}\}\)的前\(n\)项和为\(T_{n}\);
    \((Ⅲ)\)设\(c_{n}=\sqrt{\dfrac{a_{n}-n}{a_{n}^{2}}}\),求证:\(c_{1}+c_{2}+c_{3}+⋅⋅⋅+c_{n}< \sqrt {n}.\)
  • 题型:解答题 题类:模拟题 难易度:较易

    年份:2021

    设\(\{a_{n}\}\)是等差数列,\(\{b_{n}\}\)是等比数列,公比大子\(0\),且\(a_{1}=b_{1}=3\),\(b_{2}=a_{3}\),\(b_{3}=4a_{2}+3.\)
    \((Ⅰ)\)求\(\{a_{n}\}\)和\(\{b_{n}\}\)的通项公式;
    \((Ⅱ)\)设数列\(\{c_{n}\}\)满足\(c_{n}=\begin{cases}{1,n\text{为奇数}}\\ {b_{\frac{n}{2}},n\text{为偶数}}\end{cases}\),求\(\sum\limits_{i=1}^{2n}a_{i}c_{i}.\)
  • 题型:解答题 题类:模拟题 难易度:较易

    年份:2021

    已知公差不为\(0\)的等差数列\(\{a_{n}\}\)满足\(a_{3}=5\),且\(a_{1}\),\(a_{2}\),\(a_{5}\)成等比数列.
    \((Ⅰ)\)求\(\{a_{n}\}\)的通项公式;
    \((Ⅱ)\)设\(b_{n}=\dfrac{1}{3^{n}}-\dfrac{1}{a_{n}a_{n+1}}\),求数列\(\{b_{n}\}\)的前\(n\)项和\(T_{n}.\)
  • 题型:解答题 题类:模拟题 难易度:较易

    年份:2021

    已知等差数列\(\{a_{n}\}\)的公差为\(d\),前\(n\)项和为\(S_{n}\),\(S_{4}=a_{1}+9\),且\(S_{9}=5a_{9}.\)
    \((1)\)求数列\(\{a_{n}\}\)的通项公式;
    \((2)\)设\(b_{n}=\dfrac{S_{n+1}-S_{n}}{S_{n}S_{n+1}}\),求数列\(\{b_{n}\}\)的前\(n\)项和\(T_{n}.\)
  • 题型:选择题 题类:模拟题 难易度:较易

    年份:2021

    已知等差数列\(\{a_{n}\}\)的前\(n\)项和为\(S_{n}\),且满足\(a_{5}\leqslant 4\),\(S_{5}\geqslant 40\),则该数列的公差\(d\)可取的值是\((\quad)\)
    A.\(3\) B.\(1\) C.\(-1\) D.\(-3\)
  • 题型:解答题 题类:模拟题 难易度:较易

    年份:2021

    已知数列\(\{a_{n}\}\)的前\(n\)项和为\(S_{n}\),\(a_{1}=1\),\(a_{2}=2\),公比为\(2\)的等比数列\(\{b_{n}\}\)的前\(n\)项和为\(T_{n}\),并且满足\(a_{n+1}\log_{2}(T_{n}+1)=2S_{n}.\)
    \((Ⅰ)\)求数列\(\{a_{n}\}\),\(\{b_{n}\}\)的通项公式;
    \((Ⅱ)\)已知\(c_{n}=\dfrac{a_{n-1}a_{2^{n}}+1}{T_{n}T_{n+1}}\),规定\(a_{0}=0\),若存在\(n\in N^{*}\)使不等式\(c_{1}+c_{2}+c_{3}+⋅⋅⋅+c_{n}< 1-\dfrac{λ}{n}\)成立,求实数\(λ\)的取值范围.
  • 题型:填空题 题类:模拟题 难易度:较易

    年份:2021

    已知等比数列\(\{a_{n}\}\)的前\(n\)项和为\(S_{n}\),\(a_{3}=7\),\(S_{3}=21\),则公比\(q=\)______.